Homework

 

The homework associated to this course will have two components: an online and handwritten homework component.
Each will count as half of the final homework grade.

The online problems cover the more routine aspects of the class. You can think of these problems as a first check of your understanding. The written homework problems are usually more conceptual. They will help you understand the concepts more completely and are often motivated by problems from the Life Sciences.

Online Homework: The online homework can be accessed through the following website
https://webwork.as.uky.edu/webwork2/MA138S17

Your username is your Link Blue user ID (use capital letters!) and your password is your student ID number.

With the online assignments you can try (most) problems as many times as you like. The system will tell you if your answer is correct or not. There is also a way to email the TA a question from each of the problem. We encourage you to use this system for online homework questions since it provides the TA with additional information about the problem you are working on. Please keep in mind that you will not get an instantaneous response to your email questions. We will always do our best to respond within 24 hours and you will probably get a faster response if you email during normal business hours. (Don't wait until the last minute!)
Also remember that more specific questions will get more informative responses from us.

Handwritten Homework: When submitting a written homework you will be required to follow these guidelines:
  1. All pages for each assignment must be stapled together with a single staple in the top left corner of the pages.
  2. If you submit your homework on pages from a notebook, then you must remove the frilly edges.
  3. You must either (a) have all problems in numerical order or (b) start every problem on the left side of the page
    so that the TA can easily find the problems that s/he chooses to grade.
You will be penalized one point for each unsatisfied item listed above on every handwritten assignment.

Section  

Online/Handwritten assigned problems (with due dates)

Warm-up
The online assignment is due on Tuesday, January 17, 11pm
6.3 The online assignment is due on Thursday, January 19, 11pm
6.3 # 17, 19, 21, 23, 31
 
The handwritten homework set 6.3 is due in recitation on Thursday, January 19
7.1 The online assignment is due on Tuesday, January 24, 11pm
7.1 # 35, 38, 47, 49, 51, 53, 55, 57
7.2 The online assignment is due on Thursday, January 26, 11pm
7.2 # 32, 35, 39, 41, 45, 49, 57, 69
 
The handwritten homework sets 7.1 and 7.2 are due in recitation on Thursday, January 26
7.3 The online assignment is due on Thursday, February 2, 11pm
7.3 # 11, 29, 33, 39, 45
 
The handwritten homework set 7.3 is due in recitation on Thursday, February 2
7.4 The online assignment is due on Tuesday, February 7, 11pm
7.4 # 9, 27, 30, 35, 37, 41
 
The handwritten homework set 7.4 is due in recitation on Thursday, February 9
8.1 The online assignment is due on Tuesday, February 21, 11pm
8.1 # 9, 15, 21, 23, 24, 29, 39, 43, 49, 53
 
The handwritten homework set 8.1 is due in recitation Tuesday, February 21
 
 
 
 
 
 
 
 

Direction fields and SAGE: In this supplementary set of notes we discuss the notion of a direction
(or slope) field
of a differential equation. SAGE is a free open-source mathematics software system.
It is easy to plot direction (slope) fields of a differential equation using SAGE.
This set of notes summarizes the details of the solutions of interesting models for the Life Sciences
(the exponential and logistic growth models; the Lotka-Volterra predator-prey model;
the Von Bertalanffy individual growth model and the Solow economic growth model).
This YouTube video How Wolves Change Rivers is a good motivation to introduce the Lotka-Volterra predator-prey model.
This is a 2014 follow-up article on the New York Times: Is the Wolf a Real American Hero?
8.2 The online assignment is due on Tuesday, February 28, 11pm
8.2 # 2, 3, 5, 6, 8, 9, 21, 25
 
The handwritten homework set 8.2 is due in recitation on Tuesday, February 28
9.1
 
A useful software to perform Gaussian Elimination: click here.
The online assignment is due on Thursday, March 2, 11pm
9.1 # 5, 17, 27, 29, 31, 35
9.2 The online assignment is due on Tuesday, March 7, 11pm
9.2 # 7, 23, 31, 35, 39, 43, 45, 49, 51, 63, 67
 
The handwritten homework sets 9.1 and 9.2 are due in recitation on Tuesday, March 7
9.3 The online assignment is due on Thursday, March 23, 11pm
9.3 # 37, 39, 41, 45, 69, 71, 73
 
The handwritten homework set 9.3 is due in recitation on Thursday, March 23
 
 
 
Fibonacci's numbers, a population model, and powers of matrices: The goal of these notes is
to illustrate an application of large powers of matrices. Our primary tools are the eigenvalues
and eigenvectors of the matrix. We illustrate this with two familiar examples.
Suppl.
 
The online assignment for the supplement on curve fitting - least squares approximation
is due on Thursday, March 30, 11pm
 
There is no handwritten homework set for the supplement on curve fitting - least squares approximation
 
 
 
Curve fitting - least squares approximation: These notes explain how to find the "best" possible
solution to a system of linear equations that has too many equations with respect to the number of
variables. This is a typical issue in the Life Sciences.
10.1 The online assignment is due on Tuesday, April 4, 11pm
10.1 # 4, 12, 15, 17, 23, 25
10.2 The online assignment is due on Thursday, April 6, 11pm
10.2 # 3, 7, 11, 17, 19, 25
 
The handwritten homework sets 10.1 and 10. 2 are due in recitation on Thursday, April 6
10.3 The online assignment is due on Sunday, April 9, 11pm
10.3 # 9, 13, 19, 23, 27, 29, 33, 41, 47, 49
10.4 The online assignment is due on Tuesday, April 11, 11pm
10.4 # 3, 7, 19, 27
 
The handwritten homework sets 10.3 and 10.4 are due in recitation on Thursday, April 13
10.4 # 29, 31, 35, 37, 39, 43
11.1 # 9, 13, 17
 
The handwritten homework sets 10.4 and 11.1 are due in recitation on Thursday, April 20
 
 
 
Direction fields of systems of linear differential equations: we analize the behavior of
several types of linear differential equations acoording to the corresponding eigenvalues
(see plots associated with DE1-DE6). The direction fields have been plotted using the software Maple.
11.1 The online assignment is due on Tuesday, April 25, 11pm
11.1 # 31, 35, 37, 47, 49, 51
  The handwritten homework set 11.1 is due in recitation on Tuesday, April 25
11.2 The online assignment is due on Friday, April 28, 11pm
11.2 # 1, 5, 19, 20
11.3 # 9, 13, 15, 17, 19, 23
11.4 # 9, 15, 17, 19, 45
 
The handwritten homework sets 11.2 and 11.3 are due in recitation on Thursday, April 27
 
 
 
 
 
Direction fields of systems of nonlinear linear differential equations:
  1. we illustrate the classic Lotka-Volterra predator-prey model -- see the plots associated with DE1-DE2.
    In DE3 we illustrate a modified Lotka-Volterra model in which the prey grows according to the logistic model;
  2. we illustrate various types of population dynamics related to the Lotka-Volterra competing species model --
    see plots associated with DE4-DE6. In DE4 species 1 (=x(t)) and 2 (=y(t)) cohexist; in DE5 either species 1 or 2
    wins depending on the initial condition; in DE6 one of the two species outcompetes the other;
  3. we illustrate the Fitzhugh-Nagumo model (an approximation to the original Hodgkin-Huxley model)
    for neuron activity -- see plots associated with DE7;
  4. we illustrate the motion of a pendulum in the presence of air resistence -- see plots associated with DE8;
  5. In the plots associated with DE9-DE10 we give two systems of nonlinear differential equations which have
    the same linearization at the equilibrium (0,0). In DE9 the origin is an unstable spiral whereas in DE10
    the origin is a stable spiral. These examples illustrate the failure of the linearization criterion when
    the eigenvalues at the equilibrium are purely imaginary.
All direction fields and plots have been created using the software Maple.